Crystallization method and bioavailability

ABSTRACT

Preparation, in-vitro and in vivo characterization of novel forms of (1-hydroxy-2-imidazol-1-yl-1-phosphono-ethyl)phosphonic acid, suitable for pharmaceutical compositions in drug delivery systems for humans.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.12/847,568, filed Jul. 30, 2010; which claims priority to U.S.application Ser. No. 61/230,222, filed Jul. 31, 2009; to U.S.application 61/288,036, filed Dec. 18, 2009; to U.S. application61/302,110, filed Feb. 6, 2010; to U.S. application 61/312,879, filedMar. 11, 2010; to U.S. application 61/318,503, filed Mar. 29, 2010; andto U.S. application 61/359,544, filed Jun. 29, 2010; each of which isincorporated herein by reference.

FIELD OF THE INVENTION

This disclosure pertains to improvement of the aqueous solubility andpermeability of poorly permeable and sparingly water soluble drugcompounds through generating novel crystalline forms of such drugs. Thenovel forms include but are not limited to cocrystals, salts, hydrates,solvates, solvates of salts, and mixtures thereof. Methods for thepreparation and pharmaceutical compositions suitable for drug deliverysystems that include one or more of these new forms are disclosed.

BACKGROUND OF THE INVENTION

Many Biopharmaceutic Classification System (BCS) class III or IV drugssuffer from the lack of gastrointestinal (GI) tract membranepermeability leading to poor oral bioavailability. Different strategieshave been implemented to improve the permeability and subsequently theoral bioavailability of such drugs. For example, the U.S. patentapplication 20060068010 describes a formulation method for improving thepermeability of drugs and subsequently increasing their bioavailabilityby granulation of the physical solid mixture of the drug with one ormore amino acids, at least one inter-granular hydrophilic polymer, andan additional immediate release excipient. Another application WO200602009 A1 disclosed the increase of the oral bioavailability forpoorly permeable drugs such as bisphosphonates; risedronate as one ofthose drugs was mixed with a chelating agent such asethylenediaminetetraacetate (EDTA) and other excipients to make an oraldosage form. Yet another application, WO 2007093226 A1, describes amethod for improving the bioavailability of ibandronate by generating aphysical mixture of the drug together with a modified amino acid(acylation or sulphonation of the amino group with phenyl or cyclohexyl)and other excipients. Another application WO 2003007916 A1 reports agastric retention system to improve the bioavailability of a poorlypermeable drug, alendronate, which was orally formulated with vitamin Dand released an hour after the immediate release of vitamin D. WO2006080780 discloses yet another method to improve the permeability andbioavailability of alendronate, a poorly permeable bisphosphonate, bymixing it with a biocompatible cationic polymer (i.e. water solublechitosan) with up to a 10:1 weight ratio of the chitosan to the drug,while the resulting mixture can be formulated into a solid or liquidoral dosage form. A further method of improving permeability of drugmaterials was discussed in the U.S. patent application 2007/014319 A1,where an oral dosage form was formulated by a powder mixture of abisphosphonic acid (e.g. zoledronic acid) together with an inactiveingredient (either an ester of a medium chain fatty acid or a lipophilicpolyethylene glycol ester). A similar approach was disclosed in the USapplication 2007/0238707 A1 where a medium length fatty acid or itsderivative (6-20 carbon atom fatty acid chain) was physically mixed witha poorly permeable drug (e.g. zoledronic acid) in a capsule that wasenterically coated.

Zoledronic acid, known as(1-hydroxy-2-imidazol-1-yl-1-phosphono-ethyl)phosphonic acid, isdepicted by the following chemical structure:

Zoledronic acid is a third generation bisphosphonate which far exceedsthe previous generations in terms of efficacy and is used predominatelyfor indications of osteoporosis, Paget's disease, hypercalcemia, andinhibition of bone metastasis. It was originally developed by Novartisand marketed as the monohydrate under the brand names Zometa® andReclast®. Zoledronic acid was first approved in 2000 for the treatmentof hypercalcemia in Canada. It was later approved for use in the US forhypercalcemia in 2001, for multiple myeloma and bone metastases fromsolid tumors in 2002, and for osteoporosis and Paget's disease in 2007.Clinical trials have also been conducted or are on-going exploring theuse of zoledronic acid in neoadjuvant or adjuvant cancer therapy,Coleman, et al., British J Cancer 2010; 102(7):1099-1105, Gnant, et al.,New England J Medicine. 2009, 360 (17):679-691 and Davies, et al. JClinical Oncology, 2010, 28(7s): Abstract 8021. Zoledronic acid isadministered as an intravenous (IV) dose of 4 mg over 15 minutes forhypercalcemia of malignancy, multiple myeloma, and bone metastases fromsolid tumors, while an IV dose of 5 mg over 15 minutes is used forosteoporosis and Paget's disease.

Zoledronic acid is sparingly soluble in water and 0.1 N HCl solution butis freely soluble in 0.1 N NaOH. Zoledronic acid is practicallyinsoluble in various organic solvents.

Much effort has been taken to generate novel oral formulations ofzoledronic acid through crystallization and metal salt formation toimprove its aqueous solubility, permeability, and subsequent oralbioavailability. A crystalline trihydrate was disclosed in the U.S.Patent application 2006/0178439 A1 and world patent applicationWO2007/032808. Seven hydrated forms, an amorphous form, three monosodiumsalts, and eleven disodium salts with varying degrees of hydration ofzoledronic acid were also disclosed in the patent applicationWO2005/005447 A2. Zoledronate metal salts including Na⁺, Mg²⁺, Zn²⁺ werereported in the journal of Drugs of the Future (Sorbera et al, 25(3),Drugs of the Future, (2000)). Zoledronate, zoledronic, or zoledronicsalt represents the ionic form of zoledronic acid. Patent applicationWO2008/064849 A1 from Novartis disclosed additional metal saltsincluding two Ca²⁺ salts, two Zn²⁺ salts, one Mg²⁺ salt, as well as amonohydrate, a trihydrate, an amorphous form, and an anhydrous form.

According to the US Food and Drug Administration (FDA) Summary Basis ofApproval (SBA) for zoledronic acid, the poor oral bioavailability(approximately 1%), is partially due to its poor permeability in the GItract. It was also noted that insoluble metal complexes were formed inthe upper intestines, most commonly with calcium. Zoledronic acid hasalso been shown to cause severe gastric and intestinal irritations.

All of the above attempts to improve the oral bioavailability ofzoledronic acid were either focused on improving the aqueous solubilityby generating novel solid forms, or by mixing the drug with an inactiveingredient that has enhanced GI tract permeability. The improvement ofaqueous solubility failed to improve the bioavailability of zoledronicacid, since the formation of insoluble zoledronate calcium complexes isunlikely to be prevented. On the other hand, powder mixtures of thepoorly permeable drug with inactive permeability enhancers improved thebioavailability of the drug. This approach of mixing different materialswith different particle sizes and size distributions could result in apoor blend/physical mixture uniformity. Constituents of the mixturecould also segregate during transportation or with shaking andvibration. Additionally, the powder blends require rigorousbatch-to-batch consistency to ensure the uniformity of the blendbatches.

To the best of the inventors' knowledge, no attempt has been made priorto this invention towards a deliberate molecular design to create amolecular complex of the drug and additional component(s) (coformer(s))in a single crystalline structure. The benefit of such design can leadto the elimination of all the batch to batch blend uniformity andparticle segregation problems that powder blends often suffer from. Inaddition, this invention simplifies the manufacturing of the soliddosage form (comprised of drug and excipient) such that the final soliddosage form is, in one embodiment, a powder of the molecular complex.

Additionally, the resulting molecular complexes possess very differentphysicochemical properties compared to the parent drug, coformer ortheir physical mixture. These properties include but are not limited tomelting point, thermal and electrical conductivity, aqueous solubility,rate of dissolution and permeability across the GI tract membrane. Thepermeability improvement could result in the enhancement of the oralbioavailability of the BCS class III and IV drugs. This is the firsttime that the concept of a molecular complex by design was employed toimprove the permeability and subsequent bioavailability of a poorlypermeable drug such as zoledronic acid. The mechanisms behind thepermeability enhancement, however, are not fully understood.

The upward trend in the use of oral drugs continues especially in lightof the goal to decrease the overall cost of healthcare. Orallyadministered drugs are becoming more preferred in various therapeuticareas including cancers. Clearly, there is an opportunity to create oraldosage forms of IV drugs where oral dosage forms do not yet exist due totheir poor aqueous solubility and/or poor permeability providing a clearclinical benefit for patients. Given the fact that zoledronic acid isonly approved for IV administration, there is a need to develop an oraldosage form of zoledronic acid. By using pharmaceutically acceptableand/or approved coformers to hydrogen bond with zoledronic acid, novelmolecular complexes (e.g. cocrystals, salts, solvates, and mixturesthereof) with improve solubility and/or permeability can be created.These novel molecular complexes could be used in the development of anoral dosage form for zoledronic acid.

SUMMARY OF THE INVENTION

The present disclosure is directed towards generating new forms ofzoledronic acid, which have the therapeutic efficacy of zoledronic aciddiscussed above, with improved aqueous solubility, rate of dissolution,and/or improved permeability and thus enhanced bioavailability. Oneaspect of the present disclosure includes novel molecular complexes ofzoledronic acid that includes cocrystals, salts, and solvates (e.g.hydrates and mixed solvates as well as solvates of salts), and mixturescontaining such materials. In addition, the disclosure further includesmethods for the preparation of such complexes.

The disclosure further includes compositions of molecular complexes ofzoledronic acid suitable for incorporation in a pharmaceutical dosageform. Specific molecular complexes pertaining to the disclosure include,but are not limited to, complexes of zoledronic acid with sodium,ammonium, ammonia, L-lysine, DL-lysine, nicotinamide, adenine, andglycine. Obvious variants of the disclosed zoledronic acid forms in thedisclosure, including those described by the drawings and examples, willbe readily apparent to the person of ordinary skill in the art havingthe present disclosure and such variants are considered to be a part ofthe current invention.

The disclosure also includes results of an in vivo study of parent(pure) zoledronic acid and selected zoledronic acid complexes preparedby the methods of the invention in rat and dog models. The drugconcentrations in the rat plasma and dog serum samples along with thepharmacokinetic (PK) profiles are also included.

The foregoing and other features and advantages of the disclosedtechnology will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings.Such description is meant to be illustrative, but not limiting, of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows PXRD diffractograms of: (A=zoledronic acid, sodiumzoledronic salt and water complex), (B=NaCl), (Z1=Zoledronic acidmonohydrate), (Z3=Zoledronic acid trihydrate).

FIG. 2 is an FTIR spectrum of a complex comprising zoledronic acid,sodium zoledronic salt, and water.

FIG. 3 shows PXRD diffractograms of: (C=ammonium zoledronic salt andwater complex), (Z1=Zoledronic acid monohydrate), and (Z3=Zoledronicacid trihydrate).

FIG. 4 is an FTIR spectrum of ammonium zoledronic salt and watercomplex.

FIG. 5 shows PXRD diffractograms of: (D=zoledronic, L-lysine, and watercomplex), (E=L-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 6 is an FTIR spectrum of zoledronic, L-lysine, and water complex.

FIG. 7 shows PXRD diffractograms of: (F=zoledronic, DL-lysine, and watercomplex), (G=DL-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 8 is an FTIR spectrum of zoledronic, DL-lysine, and water complex.

FIG. 9 shows PXRD diffractograms of: (H=zoledronic acid, zoledronic,DL-lysine, ethanol, and water complex), (G=DL-lysine), (Z1=Zoledronicacid monohydrate), (Z3=Zoledronic acid trihydrate).

FIG. 10 is an FTIR spectrum of zoledronic acid, zoledronic, DL-lysine,ethanol, and water complex.

FIG. 11 shows PXRD diffractograms of: (I=zoledronic, nicotinamide, andwater complex), (J=nicotinamide), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 12 is an FTIR spectrum of zoledronic, nicotinamide, and watercomplex.

FIG. 13 shows PXRD diffractograms of: (K=zoledronic, adenine, and watercomplex), (L=adenine), (Z1=Zoledronic acid monohydrate), (Z3=Zoledronicacid trihydrate).

FIG. 14 is an FTIR spectrum of zoledronic, adenine, and water complex.

FIG. 15 shows PXRD diffractograms of: (M=zoledronic and glycinecomplex), (N=glycine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 16 is an FTIR spectrum of zoledronic and glycine complex.

FIG. 17 shows PXRD diffractograms of: (O=zoledronic diammonia watercomplex), (Z1=Zoledronic acid monohydrate), and (Z3=Zoledronic acidtrihydrate).

FIG. 18 is an FTIR spectrum of zoledronic diammonia water complex.

FIG. 19 shows PXRD diffractograms of: (P=zoledronic, DL-lysine, andwater complex), (G=DL-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 20 is an FTIR spectrum of zoledronic, DL-lysine, and water complex.

FIG. 21 shows PXRD diffractograms of: (R=zoledronic, DL-lysine, andwater complex), (G=DL-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 22 is an FTIR spectrum of zoledronic, DL-lysine, and water complex.

FIG. 23 shows PXRD diffractograms of: (R=zoledronic, DL-lysine, andwater complex), (G=DL-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 24 is an FTIR spectrum of zoledronic, DL-lysine, and water complex.

FIG. 25 shows PXRD diffractograms of: (Q=zoledronic, L-lysine, and watercomplex), (E=L-lysine), (Z1=Zoledronic acid monohydrate), and(Z3=Zoledronic acid trihydrate).

FIG. 26 is an FTIR spectrum of zoledronic, L-lysine, and water complex.

FIG. 27 shows the 24 hr rat plasma PK profile of parent zoledronic acidand zoledronic acid complexes delivered via IV, oral, and intraduodenal(ID) routes.

FIG. 28 shows the 4 hr rat plasma PK profile of parent zoledronic acidand zoledronic acid complexes delivered orally.

FIG. 29 shows the 4 hr rat plasma PK profile of parent zoledronic acidand zoledronic acid complexes delivered ID.

FIG. 30 shows the 24 hr rat plasma PK profile of parent zoledronic acidand zoledronic acid complexes delivered by oral gavage.

FIG. 31 shows the 4 hr rat plasma PK profile of parent zoledronic acidand zoledronic acid complexes delivered orally.

FIG. 32 shows the 4 hr rat plasma PK profile of parent zoledronic acidand selected zoledronic acid complexes delivered orally.

FIG. 33 shows the dog serum PK profile of parent zoledronic acid andzoledronic acid complexes delivered IV and orally.

FIG. 34 shows the 4 hr dog serum PK profile of parent zoledronic acidand zoledronic acid complexes delivered IV and orally.

FIG. 35 shows the dog serum PK profile of parent zoledronic acid andzoledronic acid complexes delivered IV and orally; enteric andnon-enteric coated capsules.

FIG. 36 shows the 6 hr dog serum PK profile of parent zoledronic acidand zoledronic acid complexes delivered IV and orally; enteric andnon-enteric coated capsules.

FIG. 37 shows the dog PK data for the enteric and non-enteric coatedhard gelatin capsules.

FIG. 38 shows the 24 hr dog serum PK profile of zoledronic acidcomplexes delivered IV and orally.

FIG. 39 shows the 4 hr dog serum PK profile of zoledronic acid complexesdelivered IV and orally.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In general, active pharmaceutical ingredients (APIs) in thepharmaceutical compositions can be prepared in a variety of differentforms including prodrugs, amorphous forms, solvates, hydrates,cocrystals, salts and polymorphs. The discovery of novel API forms mayprovide an opportunity to improve the performance characteristics of apharmaceutical product. Additionally, discovery of drug forms expandsthe array of resources available for designing pharmaceutical dosageforms with targeted release profiles or other desired characteristics.

A specific characteristic that can be targeted includes the crystal formof an API. The alteration of the crystal form of a given API wouldresult in the modification of the physical properties of the targetmolecule. For example, various polymorphs of a given API exhibitdifferent aqueous solubility, while the thermodynamically stablepolymorph would exhibit a lower solubility than the meta-stablepolymorph. In addition, pharmaceutical polymorphs can also differ inproperties such as rate of dissolution, shelf life, bioavailability,morphology, vapor pressure, density, color, and compressibility.Accordingly, it is desirable to enhance the properties of an API byforming molecular complexes such as a cocrystal, a salt, a solvate orhydrate with respect to aqueous solubility, rate of dissolution,bioavailability, Cmax, Tmax, physicochemical stability, down-streamprocessibility (e.g. flowability compressibility, degree of brittleness,particle size manipulation), decrease in polymorphic form diversity,toxicity, taste, production costs, and manufacturing methods.

In the development of orally delivered drugs, it is often advantageousto have novel crystal forms of such drugs that possess improvedproperties, including increased aqueous solubility and stability. Inmany cases, the dissolution rate increase of drugs is desired as itwould potentially increase their bioavailability. This also applies tothe development of novel forms of zoledronic acid which, whenadministered orally to a subject could achieve a greater or similarbioavailability and PK profile when compared to an IV or otherformulations on a dose-for-dose basis.

Cocrystals, salts, solvates and hydrates of zoledronic acid of thepresent invention could give rise to improved properties of zoledronicacid. For example, a new form of zoledronic acid is particularlyadvantageous if it can improve the bioavailability of orally deliveredzoledronic acid. A number of novel zoledronic acid forms have beensynthesized, characterized, and disclosed herein. Of particular interestare the zoledronic acid and the standard amino acids since they haveindicated enhanced permeability compared with other molecular complexesof zoledronic acid. The mechanism of enhanced permeability of thesecomplexes is not yet understood and, while not to be bound by thisexplanation, it is possible that they moderate the formation of theinsoluble Ca²⁺ zoledronate salt resulting in more zoledronic acid to beabsorbed paracellularly through the tight junctions. It must be stressedthat this is a possible mechanism of enhanced permeability.

Schematic diagrams for zoledronic acid:amino acid complexes (azoledronic acid:lysine complex and a zoledronic acid:glycine complex,two embodiments of the invention) are shown below. The diagrams show amolecular structure of the complex and possible interactions between theconstituents of the complex which is different from the physical mix ofthe constituents.

1. Zoledronic Acid: Lysine Complex

2. Zoledronic Acid: Glycine Complex

These represent one of the arrangements that molecules of the drug andthe standard amino acids coformers could interact to form a stablecomplex that even when stressed thermally at elevated relative humidity(RH) environment have not displayed any signs of deterioration ordisintegration to its original constituents. Such stability can beattributed to the hydrogen bonding (dashed line in the box) in thesemolecular complexes. When packing in a crystal structure these complexeshave very different morphologies to that of its constituents or theirphysical mix as indicated by their powder X-ray diffraction (PXRD)patterns and therefore would possess different, unpredictablephysicochemical properties.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic acid, sodium zoledronate and water complex,characterized by an X-ray powder diffraction pattern having strong peaksat about 8.1, 13.3, 21.5, 24.6, and 25.6±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of ammonium zoledronic salt and water complex, characterized byan X-ray powder diffraction pattern having strong peaks at about 11.0,14.6, 15.4, 19.9, and 29.4±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic, L-lysine, and water complex, characterized by anX-ray powder diffraction pattern having strong peaks at about 9.0, 14.4,18.1, 26.0, and 29.6±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic, DL-lysine, and water complex, characterized byan X-ray powder diffraction pattern having strong peaks at about 9.1,14.7, 18.0, 21.2, and 26.0±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic acid, zoledronic, DL-lysine, ethanol, and watercomplex, characterized by an X-ray powder diffraction pattern havingstrong peaks at about 8.8, 9.7, 17.6, 23.1, and 26.5±0.2 degreestwo-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic acid, nicotinamide, and water complex,characterized by an X-ray powder diffraction pattern having strong peaksat about 13.1, 15.2, 21.0, 23.9, and 26.5±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic, adenine, and water complex, characterized by anX-ray powder diffraction pattern having strong peaks at about 13.6,15.9, 19.7, 27.9, and 29.5±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic and glycine complex, characterized by an X-raypowder diffraction pattern having strong peaks at about 10.2, 17.8,19.9, 22.9, and 28.1±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic diammonia water complex, characterized by anX-ray powder diffraction pattern having strong peaks at about 12.2,13.0, 14.1, 17.1, and 19.3±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic, DL-lysine, and water complex, characterized byan X-ray powder diffraction pattern having strong peaks at about 8.3,11.8, 12.3, 15.8, and 20.8±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic acid, L-lysine, and water complex, characterizedby an X-ray powder diffraction pattern having strong peaks at about 9.6,10.7, 14.3, 21.4, 23.5±0.2 degrees two-theta.

The present invention provides a new crystal form of zoledronic acid inthe form of zoledronic, DL-lysine, and water complex, characterized byan X-ray powder diffraction pattern having strong peaks at about 9.7,10.8, 14.4, 18.9, 21.4±0.2 degrees two-theta.

The present invention provides rat plasma or dog serum concentrationlevels and PK profiles of IV, orally and ID delivered zoledronic acidparent compound versus complexes of zoledronic acid created using themethod of this invention.

Accordingly, in a first aspect, the present invention includes complexesof zoledronic acid with sodium, ammonium, ammonia, L-lysine, DL-lysine,nicotinamide, adenine and glycine which are capable of complexing in thesolid-state, for example, through dry or solvent-drop grinding (liquidassisted grinding), heating or solvent evaporation of their solution insingle or mixed solvent systems, slurry suspension, supercritical fluidsor other techniques known to a person skilled in the art.

Another aspect of the invention provides zoledronic and nicotinamidecomplex by dissolving both compounds in water:ethylacetate (1:1 v/v) andallowing the solvent mixtures to evaporate to form crystalline material.

Another aspect of the invention provides zoledronic and glycine solidcomplex from dissolving both compounds in water, and allowing thesolvent to evaporate to form crystalline material.

Another aspect of the invention provides complexes of zoledronic acidand sodium, ammonium, ammonia, L-lysine, DL-lysine, nicotinamide,adenine and glycine suitable for a pharmaceutical formulation than canbe delivered orally to the human body. The pharmaceutical formulationcontains a therapeutically effective amount of at least one of the novelmolecular complexes of zoledronic acid according to the invention and atleast one pharmaceutically acceptable carrier, (also known in the art asa pharmaceutically acceptable excipient). The novel molecular complexesof zoledronic acid are therapeutically useful for the treatment and/orprevention of disease states associated with osteoporosis, hypercalcemia(TIH), cancer induced bone metastasis, Paget's disease or adjuvant orneoadjuvant therapies, discussed above.

The invention also relates to methods of treatment using novel molecularcomplexes of zoledronic acid of the invention or a pharmaceuticalformulation containing them. A pharmaceutical formulation of theinvention may be in any pharmaceutical form which contains a novelmolecular complex of zoledronic acid according to the invention. Thepharmaceutical formulation may be, for example, a tablet, capsule,liquid suspension, injectable, suppository, topical, or transdermal. Thepharmaceutical formulations generally contain about 1% to about 99% byweight of at least one novel molecular complex of zoledronic acid of theinvention and 99% to 1% by weight of a suitable pharmaceuticalexcipient.

Complexes of zoledronic acid and sodium, ammonium, ammonia, L-lysine,DL-lysine, nicotinamide, adenine, and glycine have been observed bytheir PXRD patterns and FTIR spectra.

Another aspect of the invention provides in-vivo data in rats concerningthe oral bioavailability of zoledronic acid delivered orally andintraduodenally.

Another aspect of the invention provides PK profiles of the parentcompound delivered by different routes; IV, oral and ID.

Another aspect of the invention provides modified oral bioavailabilityvalues of novel zoledronic acid complexes prepared by the method ofinvention, compared with the orally delivered parent compound.

Another aspect of the invention provides the addition of excess at leastone coformer to the zoledronic acid complexes, which may be the same asthe coformer in the complex, a different coformer, or a mixture thereof.

Another aspect of the invention provides a method where the excesscocrystal formers consist of standard amino acids.

Another aspect of the invention provides modified PK profiles ofzoledronic acid complexes with excess cocrystal formers, compared withthat of the orally delivered parent compound.

Another aspect of the invention provides improved aqueous solubility ofnovel zoledronic acid complexes compared with the parent compound.

Another aspect of the invention provides modified oral bioavailabilityvalues of novel zoledronic acid complexes with excess cocrystal formers,compared with the orally delivered parent compound.

Another aspect of the invention provides in vivo data in dogs concerningthe oral bioavailability of zoledronic acid delivered IV or orally.

Another aspect of the invention provides modified oral bioavailabilityvalues in dogs of novel zoledronic acid complexes prepared by the methodof invention delivered in gelatin capsules compared with the orallydelivered parent compound.

Another aspect of the invention provides modified oral bioavailabilityvalues in dogs of novel zoledronic acid complexes prepared by the methodof invention delivered in enteric coated gel capsules compared with thatof the parent compound.

Another aspect of the invention provides substantial improvement in oralbioavailability values in dogs of novel zoledronic acid complexes withexcess cocrystal formers prepared by the method of invention deliveredin hard gelatin capsules.

Another aspect of the invention provides slight improvement in oralbioavailability values for zoledronic acid in dogs via zoledronic acidand novel zoledronic acid complexes orally delivered through entericcoated capsules.

Another aspect of the invention provides a reduced oral bioavailabilityvalues for zoledronic acid in dogs via novel zoledronic acid complexeswith excess physical mix of coformer.

Another aspect of the invention provides a molecular complex comprisinga bisphosphonic acid or salt thereof and at least one coformer, whereinthe bioavailability of the bisphosphonic acid or salt thereof from themolecular complex is greater than the bioavailability of thebisphosphonic acid or salt thereof without the coformer. Thebisphosphonic acid may be, for example, zoledronic acid, clodronic acid,tiludronic acid, pamidronic acid, alendronic acid, residronic acidibandronic acid or other bisphosphonic acids known in the art.

Another aspect of the invention provides a method for enhancing thebioavailabilty or permeability of a bisphosphonic acid comprising thestep of administering to a patient in need thereof a therapeuticallyeffective of a bisphosphonic acid in the form of a molecular complex.

The techniques and approaches set forth in the present disclosure canfurther be used by the person of ordinary skill in the art to preparevariants thereof, said variants are considered to be part of theinventive disclosure.

EXAMPLES

The following examples illustrate the invention without intending tolimit the scope of the invention.

Zoledronic acid as a starting material used in all experiments in thisdisclosure was supplied by Farmkemi Limited (Wuhan Pharma Chemical Co.),China with purity of ca. 98% and was purified further viarecrystallization from water. All other pure chemicals (AnalyticalGrade) were supplied by Sigma-Aldrich and used without furtherpurification.

Enteric coating of gelatin capsules was contracted out to AzoPharma,Hollywood, Fla., USA. A 10% w/w coating solution of Eudragit L100-55,and triethyl citrate, 9.09 and 0.91 w/w % respectively, in purifiedwater and acetone was used in the Vector LDCS pan coater to achieve auniform coating layer on the capsules. The coating uniformity andfunctionality for duodenal delivery was tested by 2 hr dissolution insimulated gastric fluid stirred at 75 rpm and 37° C. All capsulesremained closed for the duration of this test.

Solid Phase Characterization

Analytical techniques used to observe the crystalline forms includepowder X-ray diffraction (PXRD) and Fourier transform infraredspectroscopy (FTIR). The particular methodology used in such analyticaltechniques should be viewed as illustrative, and not limiting in thecontext of data collection. For example, the particular instrumentationused to collect data may vary; routine operator error or calibrationstandards may vary; sample preparation method may vary (for example, theuse of the KBr disk or Nujol mull technique for FTIR analysis).

Fourier Transform FTIR Spectroscopy (FTIR): FTIR analysis was performedon a Perkin Elmer Spectrum 100 FTIR spectrometer equipped with asolid-state ATR accessory.

Powder X-Ray Diffraction (PXRD): All zoledronic acid molecular complexproducts were observed by a D-8 Bruker X-ray Powder Diffractometer usingCu Kα (λ=1.540562 Å), 40 kV, 40 mA. The data were collected over anangular range of 3° to 40° 2θ in continuous scan mode at roomtemperature using a step size of 0.05° 2θ and a scan speed of 6.17°/min.

Example 1 Preparation of Zoledronic Acid, Sodium Zoledronic Salt, andWater Complex

200 mg of zoledronic acid was slurried with 180 mg of sodium chloride in1 mL of 1:1 ethanol:water overnight. The material was filtered andrinsed. The particulate material was gathered and stored in a screw capvial for subsequent analysis. The material was characterized by PXRD andFTIR corresponding to FIG. 1 and FIG. 2, respectively.

Example 2 Preparation of Ammonium Zoledronic Salt and Water Complex

300 mg of zoledronic acid was slurried in 7N ammonia in methanolovernight. The material was filtered and rinsed. The particulatematerial was dissolved in water and left to evaporate at ambientconditions to obtain colorless plates after 1 week. The material wascharacterized by PXRD and FTIR corresponding to FIG. 3 and FIG. 4,respectively.

Example 3 Preparation of Zoledronic, L-lysine, and Water Complex

200 mg of zoledronic acid and 54 mg of L-lysine were slurried in 2 mL oftetrahydrofuran and 200 μl of water overnight. The solids gathered afterfiltration were dried and stored in a screw cap vials for subsequentanalysis. The material was characterized by PXRD and FTIR correspondingto FIG. 5 and FIG. 6, respectively.

Example 4 Preparation of Zoledronic, DL-lysine, and Water Complex

204 mg of zoledronic acid and 59 mg of DL-lysine were slurried in 2 mLof tetrahydrofuran and 200 μl of water overnight. The solids gatheredafter filtration were dried and stored in a screw cap vials forsubsequent analysis. The material was characterized by PXRD and FTIRcorresponding to FIG. 7 and FIG. 8 respectively.

Example 5 Preparation of Zoledronic Acid, Zoledronic, DL-lysine,Ethanol, and Water Complex

103 mg of zoledronic acid and 54 mg of DL-lysine were dissolved in 400μl of water, capped and stirred overnight. The next day 0.25 mL ofethanol was added drop wise. The vial was capped with a screw cap vialand after 1 day crystals appeared and were filtered off. The materialwas stored for subsequent analysis. The material was characterized byPXRD and FTIR corresponding to FIG. 9 and FIG. 10 respectively.

Example 6 Preparation of Zoledronic, Nicotinamide, and Water Complex bySolvent-Drop Grinding

99 mg of zoledronic acid was ground with 44 mg of nicotinamide and 40 μlof water was added to the solid mixture. The solids gathered aftergrinding were stored in screw cap vials for subsequent analysis. Thematerial was characterized by PXRD and FTIR corresponding to FIG. 11 andFIG. 12, respectively.

Example 7 Preparation of Zoledronic, Nicotinamide, and Water Complexfrom Solution Crystallization

25 mg of zoledronic acid and 138 mg of nicotinamide were dissolved in 2mL of a water:ethylacetate mix (1:1 v/v). The solution was then allowedto stand for several hours to effect the slow evaporation of solvent.The solids gathered were characterized and produced very similar PXRDand FTIR patterns to that of Example 7 product.

Example 8 Preparation of Zoledronic, Adenine, and Water Complex bySolvent-Drop Grinding

96 mg of zoledronic acid was ground with 65 mg of adenine and 60 μL ofwater was added to the solid mixture. The solids gathered after grindingwere stored in screw cap vials for subsequent analysis. The material wascharacterized by PXRD and FTIR corresponding to FIG. 13 and FIG. 14,respectively.

Example 9 Preparation of Zoledronic, Adenine, and Water Complex fromSolution Slurry

99 mg of zoledronic acid and 54 mg of adenine were slurried in 2 mL of awater:ethanol mix (1:1 v/v) overnight. The solids gathered afterfiltration were dried, characterized and produced very similar PXRD andFTIR patterns to that of Example 8 product.

Example 10 Preparation of Zoledronic and Glycine Complex

178 mg of zoledronic acid and 45 mg of glycine were slurried in 2 mL ofwater overnight. The solids gathered after filtration were dried andstored in a screw cap vials for subsequent analysis. The material wascharacterized by PXRD and FTIR corresponding to FIG. 15 and FIG. 16,respectively.

Example 11 Preparation of Zoledronic Diammonia Water Complex

1.5 g of zoledronic acid was slurried in 7N ammonia in methanolovernight. The material was filtered and rinsed. The particulatematerial was dissolved in water with medium heat and left to evaporateat ambient conditions to obtain colorless blocks after 1 day. Thematerial was characterized by PXRD and FTIR corresponding to FIG. 17 andFIG. 18, respectively.

Example 12 Preparation of Zoledronic, DL-lysine, and Water Complex

200 mg of zoledronic acid and 102 mg of DL-lysine were slurried in 2 mLof tetrahydrofuran and 400 μl of water overnight. The solids gatheredafter filtration were dried and stored in a screw cap vials forsubsequent analysis. The material was characterized by PXRD and FTIRcorresponding to FIG. 19 and FIG. 20 respectively.

Example 13 Preparation of Zoledronic, DL-lysine, and Water Complex

1 g of zoledronic acid and 283 mg of DL-lysine were slurried in 80 mL oftetrahydrofuran and 8 mL of water overnight. The solids gathered afterfiltration were dried and stored in a screw cap vials for subsequentanalysis. The material was characterized by PXRD and FTIR correspondingto FIG. 21 and FIG. 22 respectively.

Example 14 Preparation of Zoledronic, DL-lysine, and Water Complex byAntisolvent Method

This complex can also be prepared by the antisolvent method bydissolving 1 g of zoledronic acid and 283 mg of DL-lysine in 5 mL of hotwater and adding 40 mL of ethanol as an antisolvent stirred overnight.Similar PXRD and FTIR profiles were obtained as shown in FIGS. 23 and 24respectively.

Example 15 Preparation of Zoledronic, L-lysine, and Water Complex

1 g of zoledronic acid and 255 mg of L-lysine were dissolved in 60 mL ofhot water. 100 mL of ethanol was then added as an antisolvent. Thesolids gathered after filtration were dried and stored in a screw capvials for subsequent analysis. The material was characterized by PXRDand FTIR corresponding to FIG. 25 and FIG. 26 respectively.

Example 16 The Animal PK Studies

These studies were conducted on rats and dogs as they are suitableanimal models for zoledronic acid. This can be attributed to the factthat both animals have historically been used in the safety evaluationand PK screening studies and are recommended by appropriate regulatoryagencies. In addition, rats and dogs have also been established asappropriate species for assessing the absorption of bisphosphonate drugsincluding zoledronic acid.

Pure zoledronic acid and zoledronic acid complexes prepared by themethods in this invention were delivered to the rats and dogs through IVor oral routes. Additional tests included ID administration in rats andadministration of enteric coated capsules in dogs. All compoundsdelivered were well tolerated by the animals with no adverse events orphysical abnormalities noticed.

Test Subjects: 8-week male Sprague-Dawley Rats (217-259 grams) wereobtained from Hilltop Lab Animals, Scottdale, Pa. USA. Surgicalcatheters (jugular vein and intraduodenum) were implanted to the animalsprior to the study. Beagle dogs from Marshall Farms, N.Y., USA, weighingfrom (9-12 kg) were used in this study. Surgical catheters (jugularvein) were implanted prior to the study.

Housing: Rats were individually housed in stainless steel cages toprevent catheter exteriorization. Acclimation (Pre-dose Phase) was for 1day. Dogs were already in the test facility (Absorption Systems Inc.,USA) and did not need acclimation.

Environment: Environmental controls for the animal room were set tomaintain 18 to 26° C., a relative humidity of 30 to 70%, a minimum of 10air changes/hour, and a 12-hour light/12-hour dark cycle. The light/darkcycle could be interrupted for study-related activities.

Diet: For rats, water and certified Rodent Diet #8728C (Harlan Teklad)were provided. For dogs, water and the standard dog chow diet were giventwice daily (every 12 hours).

Fasting: All test animals were fasted overnight before IV, oral, or IDadministration of zoledronic acid or zoledronic acid complexes.

Routes of Rat Dosing: Zoledronic acid and its complex formulations wereadministered through IV, oral and ID. The doses administered to allstudy rats were measured as zoledronic acid, not as the complex formcontained in the suspension:

-   -   i. IV Administration: the dose of zoledronic acid for IV        administration was 0.5 mg/kg. The dose of each rat was        calculated on a per rat basis (not on an average weight of all        the rats in the lot).    -   ii. Oral gavage administration: solid suspensions were        administered. The dose of each rat was calculated on a per rat        basis (not on an average weight of all the rats in the lot). For        solid suspensions, animals were administered 5 mg/kg of        zoledronic acid or 5 mg/kg of zoledronic acid in zoledronic acid        complexes contained in a suspension of PEG 400.    -   iii. Duodenal cannula administration: solid suspensions were        administered. The dose of each rat was calculated on a per rat        basis (not on an average weight of all the rats in the lot). For        solid suspensions, animals were administered 5 mg/kg of        zoledronic acid or 5 mg/kg of zoledronic acid in zoledronic acid        complexes contained in a suspension of PEG 400.

Routes of Dog Dosing: Zoledronic acid and its complex formulations wereadministered IV and orally. The doses administered to all study dogswere measured as zoledronic acid in each complex, not as the complexform contained in the powder in the gelatin capsule or in solution forIV:

-   -   i. IV Administration: The dose volume of each dog was adjusted        based upon the average weight of the dog.    -   ii. Oral administration: zoledronic acid and its equivalent of        zoledronic acid complex formulations were administered through        size 0 gelatin capsules based on the average weight of the dogs.    -   iii. Oral administration with enteric coated capsules:        zoledronic acid and its equivalent of zoledronic acid complex        formulations were administered through size 0 enteric coated        gelatin capsules based on the average weight of the dogs.    -   iv. Oral administration of the molecular complexes with        additional coformers: physical mixtures of zoledronic acid        complexes with additional coformers were administered through        size 0 gelatin capsules based on the average weight of the dogs.

Groups: Two major groups of animals were selected for the study.

-   -   Group 1, rats that contained four subgroups (I-IV) where the        results of each data point on the PK profile graphs was the        average drug concentration in the plasma of 3 rats.    -   Group 2, dog PK study contained three groups with subgroups (A,        B, C, D,E and F) where the results of each data point on the PK        profile graphs was the average drug concentration in the serum        of 5 dogs.

Details of Group 1 Rat Dosing

Group I (IV administration). Group members, designated IV doses arelisted below

Group # I Designation # of rats Dose* Dose volume G1 Zoledronic Acid 30.5 mg/kg 1 mLIV comparator group, was conducted to calculate MAT (mean absorptiontime) and ka (absorption rate constant) for the oral groups.Group II (oral gavage): Group designations and oral doses are listedbelow:

Dose Group # of volume # II Designation Rats Dose* mL/kg Compound G2Zoledronic Acid 3 5 mg/kg 1 mL Zoledronic acid in PEG400 G3 Solidsuspension 3 5 mg/kg 1 mL Zoledronic in PEG400 equivalent and glycinecomplex G4 Solid suspension 3 5 mg/kg 1 mL Zoledronic, in PEG400equivalent nicotinamide, and water complex G5 Solid suspension 3 5 mg/kg1 mL Zoledronic in PEG400 equivalent acid, sodium zoledronic salt, andwater complex G6 Solid suspension 3 5 mg/kg 1 mL Zoledronic, in PEG400equivalent L-lysine, and water complex G7 Solid suspension 3 5 mg/kg 1mL Zoledronic, in PEG400 equivalent DL-lysine, and water complex

Group III (ID administration): Group designations and oral doses arelisted below:

Dose Group # of volume # III Designation rats Dose* mL/kg Compound G8Zoledronic Acid 3 5 mg/kg 1 mL Zoledronic in PEG400 acid G9 Solidsuspension 3 5 mg/kg 1 mL Zoledronic in PEG400 equivalent and glycinecomplex G10 Solid suspension 3 5 mg/kg 1 mL Zoledronic, in PEG400equivalent nicotinamide, and water complex G11 Solid suspension 3 5mg/kg 1 mL Zoledronic in PEG400 equivalent acid, sodium zoledronic salt,and water complex G12 Solid suspension 3 5 mg/kg 1 mL Zoledronic, inPEG400 equivalent L-lysine, and water complex G13 Solid suspension 3 5mg/kg 1 mL Zoledronic, in PEG400 equivalent DL-lysine, and water complex

Group IV (oral gavage): Group designations and aral doses are listedbelow:

Group # of Dose Excess Excess coformer # IV Compound rats Dose volume/kgcoformer amount mg/kg G14 Zoledronic and 3 5 mg/kg 1 mL Glycine 45glycine complex, equivalent solid suspension in PEG400 G15 Zoledronicand 3 5 mg/kg 1 mL Glycine 25 glycine complex, equivalent solidsuspension in PEG400 G16 Zoledronic and 3 5 mg/kg 1 mL Glycine 5 glycinecomplex, equivalent solid suspension in PEG400 G17 Zoledronic, DL- 3 5mg/kg 1 mL DL-lysine 39.32 lysine, and water equivalent monohydratecomplex, solid suspension in PEG400 G18 Zoledronic, DL- 3 5 mg/kg 1 mLDL-lysine 28.08 lysine, and water equivalent monohydrate complex, solidsuspension in PEG400 G19 Zoledronic, DL- 3 5 mg/kg 1 mL DL-lysine 5.62lysine, and water equivalent monohydrate complex, solid suspension inPEG400 G20 Zoledronic, DL- 3 5 mg/kg 1 mL n/a n/a lysine, and waterequivalent complex, solid suspension in PEG400

Rat blood sample collection, handling and analysis: Blood (approx. 300μL per sample) samples were withdrawn from each of 3 animals in Group I(IV administration) at eight (8) time points: 5 min, 15 min, 30 min, 1hr, 2 hr, 4 hr, 8 hr, and 24 hrs, after initial administration ofzoledronic acid or its complexes, into EDTA plasma tubes. Plasma wascollected after centrifugation at 13,000 rpm for 5 min at 4° C. andimmediately frozen and stored at −60 to −80° C. till analysis.

Samples were thawed on the day of analysis and the amount of zoledronicacid in the samples was quantified by analyzed by LC/MS/MS method.

Details of Group 2 dog dosing: Prior to dosing, all dogs received a 20mL dose of citric acid (24 mg/mL in water) to lower the pH of theirstomach. After dosing capsules or IV, all dogs received additional 6.25mL citric acid solution (24 mg/mL in water) as a rinse.

Group A, (IV administration). Group members, designated IV doses arelisted below:

Group # A Designation # of fasted Dogs Dose* Dose volume Leg 1Zoledronic Acid 5 0.05 mg/kg 1 mL/kgIV comparator group, was conducted to calculate MAT (mean absorptiontime) and ka (absorption rate constant) for the oral groups.

Group B (oral administration): Group designations and oral doses arelisted below:

Dose of # of Dosing compound in fasted Solution Dosing the gelatin DogsConc. Group # B Compound Route capsules (9-12 kg) mg/mL Leg 2 Zoledronicoral 5 mg/kg 5 n/a acid equivalent Leg 3 Zoledronic oral 5 mg/kg 5 n/aand glycine equivalent complex Leg 4 Zoledronic, oral 5 mg/kg 5 n/aDL-lysine, equivalent and water complex Leg 5 Zoledronic, oral 5 mg/kg 5n/a L-lysine, equivalent and water complex Leg 6 Zoledronic, oral 5mg/kg 5 n/a DL-lysine, equivalent and water complex

Group C (oral administration): Group designations and oral doses arelisted below:

# of Dose of compound Excess Group fasted Dogs Dosing in the gelatinExcess coformer # C Compound (9-12 kg) Route capsules coformer amountLeg 7 Zoledronic acid 5 oral 56.0 mg; enteric n/a n/a monohydrate coatedcapsules Leg 8 Zoledronic and 5 oral 67.0 mg; enteric n/a n/a glycinecomplex coated capsules Leg 9 Zoledronic, DL- 5 oral 87.7 mg DL-lysine294.8 mg lysine, and monohydrate water complex Leg 10 Zoledronic, DL- 5oral 87.7 mg; enteric DL-lysine 294.8 mg lysine, and coated capsulesmonohydrate water complex Leg 11 Zoledronic, DL- 5 oral 84.2 mgDL-lysine 294.8 mg lysine, and monohydrate water complex Leg 12Zoledronic, DL- 5 oral 87.7 mg; enteric n/a n/a lysine, and coatedcapsules water complex

Group D, (15 min IV infusion): Group members, designated IV doses arelisted below:

# of fasted Dogs Dosing solution Group # D Designation (9-12 kg) Dose*concentration Leg 13 Zoledronic 5 0.183 mg/kg IV 0.1 mg/mL Acid

Group E, (oral administration): Group members, designated IV doses arelisted below:

# of Dose of compound Excess Group fasted Dogs Dosing in the gelatinExcess coformer # E Compound (9-12 kg) Route capsules coformer amountLeg 14 Zoledronic, DL- 2.1 oral 35.4 mg DL-lysine 123.8 mg lysine, andmonohydrate water complex Leg 15 Zoledronic and 5 oral 67.0 mg DL-lysine294.8 mg glycine complex monohydrate Leg 16 Zoledronic, L- 5 oral 87.7mg DL-lysine 294.8 mg lysine, and monohydrate water complex Leg 17Zoledronic, DL- 2.1 oral 35.4 mg DL-lysine 294.8 mg lysine, andmonohydrate water complex

Group F, (15 min IV infusion): Group members, designated IV doses arelisted below:

Group # of fasted Dosing solution # F Designation Dogs (9-12 kg) Dose*concentration Leg 18 Zoledronic 5 0.12 mg/kg IV 0.1 mg/mL Acid infusion

After initial administration of zoledronic acid or its complexes, blood(approx. 2.5 mL per sample) was withdrawn from each of 5 animals inGroup A (IV administration) at 15 time points: Pre-dose (0), 2, 5, 10,15, 30, 45 min, 1, 1.5, 2, 4, 6, 8, 24 and 48 hrs and at 13 time pointsfor Group B (oral administration): Pre-dose (0), 5, 10, 15, 30, 45 min,1, 1.5, 2, 4, 6, 8, and 24 hrs. Blood samples were placed without theuse of an anticoagulant and allowed to sit at room temperature forapproximately 30 minutes. Samples were then centrifuged at a temperatureof 4° C., at a speed of 13,000 rpm, for 5 minutes. Serum was collectedand split into two aliquots and stored frozen (−80° C.) till analysis.Samples were thawed on the day of analysis and processed usinganalytical procedures for zoledronic acid containing an LC/MS/MSanalysis method.

Animal PK Studies Results

Rat study: The results of the first rat study are summarized in Table 1;the concentrations (ng/mL) of zoledronic acid in the plasma samples arethe average values of the analytical results of 3 rats. In addition, thePK profiles of the IV, oral and ID groups are shown in FIG. 27. Theprofiles of oral and ID groups are shown in FIGS. 28 and 29. It suggeststhat some zoledronic acid complexes have improved oral bioavailabilitycompared with that of the parent zoledronic acid. The complexes withimproved bioavailability were further tested in a second rat PK study inwhich excess coformers were added to the zoledronic acid complexes andthen administered to rats by oral gavage. The results of this secondstudy are summarized in Table 2 and their PK profiles are shown in FIGS.30, 31 and 32. These figures show improved bioavailabilities of severalzoledronic acid complexes with excess coformers.

Dog study: The results of the first dog study are summarized in Table 3.The concentrations (ng/mL) of zoledronic acid are the average values ofthe analytical results of 5 dogs. The PK profiles of the IV and oralgroups are shown in FIGS. 33 and 34 which represent the first four hoursof the 48 hr PK profile. These results and FIG. 34 suggest that most ifnot all zoledronic acid complexes have achieved improved oralbioavailability compared to that of the parent zoledronic acid deliveredorally.

The results of the second dog study are summarized in Table 4; theconcentrations (ng/mL) of zoledronic acid shown are the average valuesof the analytical results of 5 dogs. The PK profiles of the IV and oralgroups are shown in FIGS. 35 and 36. FIG. 36 represents the first 6hours of the 24 hour PK profile. These results and FIG. 35 suggest thatmost if not all zoledronic acid complexes have achieved improved oralbioavailability compared with that of the parent zoledronic aciddelivered orally. Specifically, there was a significant improvement inzoledronic acid bioavailability for the novel zoledronic acid complexeswith excess amino acid coformer (Leg 11, FIG. 37) compared to that ofthe parent drug. The results have also shown that there was improvementin the bioavailability of the enterically coated capsules compared withthe non-enterically coated capsules (FIG. 37, Legs 7 and 2, Legs 8 and3, Legs 12 and 4), but surprisingly the bioavailability wassignificantly altered when excess amino acid coformer was added to forma physical mixture to the enterically coated capsules (FIG. 37, Legs 9and 10). The reason behind it is not fully understood.

The results have shown that there is a slight increase in the oralbioavailability of zoledronic acid from the enteric coated capsulesfilled with neat (i.e. with no excess coformer) zoledronic acid aminoacid complex. Therefore, it is expected that the excess coformer withthe novel zoledronic acid complexes would also lead to increasedbioavailability when delivered in enterically coated capsules.Surprisingly, when excess coformer was added to the zoledronic acid, thebioavailability of the enterically coated capsules was lower than thatof the non-enterically coated capsules. This suggests that a physicalpowder mixture of the molecular complex and excess coformer mightdecrease the bioavailability when delivered to the duodenum.

The analytical results of the third dog study are shown in Table 5,which contains averaged data from five dogs. The PK profiles of the IVand oral groups are shown in FIGS. 38 and 39. FIG. 39 represents thefirst 4 hours of the 24 hour PK profile.

TABLE 1 Rat plasma concentrations for pure zoledronic acid andzoledronic acid complexes via different routes of delivery. Averageplasma concentration Group Dosing Time of 3 Rats # Complex Route Vehicle(hour) (ng/mL) G1 Zoledronic acid IV Water 0.083333 3254.05 0.25 1950.620.5 1128.75 1 404.28 2 112.68 4 30.46 8 10.66 24 2.98 G2 Zoledronic acidPO PEG 0.25 330.06 400 0.5 267.45 1 138.91 2 47.72 4 11.78 8 2.00 240.00 G3 Zoledronic and glycine PO PEG 0.25 648.01 complex 400 0.5 435.381 200.88 4 12.78 8 1.46 24 0.00 G4 Zoledronic, nicotinamide, PO PEG 4000.25 434.61 and water complex 0.5 304.94 1 122.35 4 7.68 8 1.82 24 0.00G5 Zoledronic acid, sodium PO PEG 400 0.25 278.47 zoledronic salt, andwater 0.5 280.20 complex 1 171.59 4 13.42 8 1.78 24 0.00 G6 Zoledronic,L-lysine, PO PEG 0.25 258.43 and water complex 400 0.5 249.82 1 184.95 428.70 8 3.27 24 0.00 G7 Zoledronic, DL-lysine, PO PEG 0.25 494.31 andwater complex 400 0.5 379.27 1 213.48 4 14.57 8 3.42 24 0.00 G8Zoledronic acid ID PEG 0.25 145.67 400 0.5 109.92 1 47.36 2 12.94 4 3.858 0.97 24 0.00 G9 Zoledronic and glycine ID PEG 0.25 86.51 complex 400 133.93 4 1.75 8 1.55 24 0.00 G10 Zoledronic, nicotinamide, ID PEG 0.2569.71 and water complex 400 1 21.03 4 0.86 8 0.00 24 0.00 G11 Zoledronicacid, sodium ID PEG 0.25 39.99 zoledronic salt, and water 400 1 18.50complex 4 0.71 8 0.00 24 0.00 G12 Zoledronic, L-lysine, and ID PEG 0.2591.21 water complex 400 1 26.53 4 0.74 8 0.00 24 0.00 G13 Zoledronic,DL-lysine, ID PEG 0.25 98.25 and water complex 400 1 34.61 4 2.65 8 1.0224 0.80

TABLE 2 Rat plasma concentrations for zoledronic acid complexes withexcess coformers, delivered by oral gavage Average plasma concentrationDosing Time of 3 Rats Group # Complex Route Vehicle (hour) (ng/mL) G14Zoledronic and glycine PO PEG 0.0333333 14.61 complex and 45 mg/kg 4000.0833333 206.26 glycine 0.1666667 340.19 0.25 375.99 0.5 321.36 1197.01 4 17.35 24 0.00 G15 Zoledronic and glycine PO PEG 0.0333333 24.48complex and 25 mg/kg 400 0.0833333 281.08 glycine 0.1666667 502.20 0.25516.58 0.5 430.10 1 203.48 2 73.27 4 14.70 24 0.00 G16 Zoledronic andglycine PO PEG 0.0333333 60.03 complex and 5 mg/kg 400 0.0833333 365.23glycine 0.1666667 563.83 0.25 625.05 0.5 464.34 1 209.65 2 74.28 4 12.1724 0.00 G17 Zoledronic, DL-lysine, PO PEG 0.0333333 168.19 and watercomplex and 400 0.0833333 263.28 39.32 mg/kg DL-lysine 0.1666667 440.26monohydrate 0.25 456.18 0.5 385.57 1 209.26 2 85.65 4 14.58 24 0.71 G18Zoledronic, DL-lysine, PO PEG 0.0333333 219.95 and water complex and 4000.0833333 427.02 28.08 mg/kg DL-lysine 0.1666667 729.65 monohydrate 0.25777.54 0.5 632.07 1 300.86 2 100.59 4 21.14 24 0.00 G19 Zoledronic,DL-lysine, PO PEG 0.0333333 53.78 and water complex and 400 0.0833333394.73 5.62 mg/kg DL-lysine 0.1666667 649.52 monohydrate 0.25 669.20 0.5530.00 1 265.20 2 73.31 4 15.41 24 0.00 G20 Zoledronic, DL-lysine, POPEG 0.0333333 103.13 and water complex 400 0.0833333 352.18 0.1666667475.33 0.25 505.48 0.5 431.41 1 224.56 2 69.95 4 14.96 24 0.00

TABLE 3 Dog serum concentrations for pure zoledronic acid and zoledronicacid complexes via different routes of delivery (IV and oral). Averageserum concentration Dosing Time of 5 dogs Leg # Complex Route Vehicle(hour) (ng/mL) 1 0.05 mg/kg IV Saline 0 0.00 Zoledronic acid solution0.0333 413.44 0.0833 311.68 0.1667 228.97 0.25 178.63 0.5 111.11 0.7575.91 1 56.07 1.5 30.35 2 17.61 4 4.29 8 1.13 24 0.00 48 0.00 2 56.0 mgPO n/a 0 0.00 Zoledronic acid 0.0833 0.00 monohydrate 0.1667 0.00capsule 0.25 0.31 0.5 110.73 0.75 97.98 1 103.60 1.5 80.57 2 75.16 417.86 8 2.71 24 0.56 3 67.0 mg PO n/a 0 0.00 Zoledronic and 0.0833 2.45glycine complex 0.1667 12.75 capsule 0.25 37.07 0.5 149.20 0.75 206.14 1254.20 1.5 176.11 2 109.25 4 20.43 8 3.96 24 0.97 4 87.7 mg PO n/a 00.00 Zoledronic, 0.0833 3.11 DL-lysine, and 0.1667 6.49 water complex0.25 22.55 capsule 0.5 68.28 0.75 162.72 1 206.14 1.5 149.92 2 105.81 425.51 8 4.22 24 0.56 5 87.7 mg PO n/a 0 0.00 Zoledronic, 0.0833 0.00L-lysine, and 0.1667 3.13 water complex 0.25 10.06 capsule 0.5 188.520.75 345.28 1 318.97 1.5 180.77 2 109.23 4 23.11 8 9.73 24 1.93 6 84.2mg PO n/a 0 0.00 Zoledronic, 0.0833 0.00 DL-lysine, and 0.1667 0.20water complex 0.25 1.92 capsule 0.5 106.47 0.75 120.13 1 108.13 1.590.45 2 54.48 4 18.14 8 4.35 24 1.06

TABLE 4 Dog serum concentrations for pure zoledronic acid and zoledronicacid complexes via different routes of delivery IV and oral; enteric andnon-enteric coated gelatin capsules. Average serum concentration of 5dogs Leg # Complex Dosing Route Vehicle Time (hour) (ng/mL) 7 56.0 mgZoledronic acid PO n/a 0 0.00 monohydrate enteric 0.1667 0.00 coatedcapsule 0.25 0.00 0.5 0.00 0.75 0.00 1 9.84 1.5 86.13 2 109.37 4 107.646 14.15 8 4.57 24 0.50 8 67.0 mg Zoledronic and PO n/a 0 0.00 glycinecomplex enteric 0.1667 0.00 coated capsule 0.25 0.00 0.5 0.00 0.75 0.001 4.42 1.5 208.97 2 274.53 4 101.20 6 16.71 8 7.14 24 2.17 9 87.7 mgZoledronic, DL- PO n/a 0 0.00 lysine, and water complex 0.0833 13.31with 294.8 mg DL-lysine 0.1667 39.76 monohydrate capsule 0.25 120.41 0.5364.68 0.75 487.59 1 499.60 1.5 362.16 2 254.72 4 52.22 6 16.61 8 8.9324 2.92 10 87.7 mg Zoledronic, DL- PO n/a 0 0.00 lysine, and watercomplex 0.1667 0.00 with 294.8 mg DL-lysine 0.25 0.00 monohydrateenteric 0.5 0.00 coated capsule 0.75 3.71 1 51.32 1.5 403.15 2 309.08 444.83 6 13.15 8 7.09 24 2.66 11 84.2 mg Zoledronic, DL- PO n/a 0 0.22lysine, and water complex 0.1667 167.03 with 294.8 mg DL-lysine 0.25533.96 monohydrate capsule 0.5 878.63 0.75 838.82 1 633.50 1.5 326.63 2185.44 4 46.86 6 20.26 8 11.49 24 5.95 12 87.7 mg Zoledronic, DL- PO n/a0 0.57 lysine, and water complex 0.1667 0.60 enteric coated capsule 0.250.59 0.5 0.61 0.75 0.40 1 132.15 1.5 566.18 2 402.12 4 65.35 6 21.02 812.18 24 4.33 13 0.183 mg/kg Zoledronic IV Saline 0 0.64 acid solution0.0833 476.79 0.1667 755.68 0.25 1057.75 0.3333 745.67 0.4167 629.22 0.5522.78 0.75 342.58 1 245.36 1.25 182.59 1.5 139.77 2 80.87 4 23.40 88.78 24 3.84

TABLE 5 Dog serum concentrations for pure zoledronic acid and zoledronicacid complexes via different routes of delivery (IV and oral). Averageserum concentration Leg Dosing Time of 5 dogs # Complex Route Vehicle(hour) (ng/mL) 14 35.4 mg Zoledronic, PO n/a 0 0.00 DL-lysine, and0.0833 0.00 water complex, 0.1667 0.72 with 123.8 mg 0.25 11.40DL-lysine 0.5 78.95 monohydrate 0.75 126.46 gelatin capsule 1 137.38 1.564.73 2 33.38 4 6.14 8 0.89 24 0.00 15 67.0 mg Zoledronic PO n/a 0 0.00and glycine 0.0833 2.58 complex, with 0.1667 26.13 294.8 mg DL-lysine0.25 55.58 monohydrate gelatin 0.5 225.41 capsule 0.75 234.95 1 221.911.5 204.90 2 117.22 4 17.79 8 3.34 24 0.77 16 87.7 mg Zoledronic, PO n/a0 0.00 L- lysine, and water 0.0833 3.26 complex, with 0.1667 17.21 294.8mg DL-lysine 0.25 213.77 monohydrate 0.5 504.17 gelatin capsule 0.75436.00 1 325.21 1.5 171.42 2 100.81 4 23.38 8 4.65 24 1.48 17 35.4 mgZoledronic, PO n/a 0 0.00 DL-lysine, and 0.0833 0.00 water complex, with0.1667 13.47 294.8 mg DL-lysine 0.25 50.04 monohydrate 0.5 146.68gelatin capsule 0.75 137.24 1 116.38 1.5 66.70 2 44.94 4 8.87 8 1.58 240.21 18 0.12 mg/kg IV Saline 0 0.00 Zoledronic acid solution 0.0833309.13 0.1667 524.58 0.25 717.15 0.3333 501.70 0.4167 392.35 0.5 322.840.75 201.78 1 132.86 1.25 93.22 1.5 69.06 2 38.38 4 9.14 8 3.24 24 1.21

TABLE 6 Aqueous solubility of zoledronic acid (ZA) and novel zoledronicacid complexes at room temperature. Compound Conc. mg/mL mMol/L(complex) ZA monohydrate 1.57 5.41 ZA:Glycine 11.89 34.25 ZA:L-Lysinedihydrate 8.22 18.09 ZA:DL-Lysine dihydrate 6.85 15.08 ZA:DL-Lysinemonohydrate 13.9 31.86

The claimed invention is:
 1. A crystalline molecular complex ofzoledronic acid selected from the group consisting of: a crystallinezoledronic acid, sodium zoledronate, and water complex characterized bya powder x-ray diffraction pattern as shown in FIG. 1 or characterizedby a Fourier transform infrared spectroscopy pattern as shown in FIG. 2,a crystalline ammonium zoledronic acid salt and water complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 3or characterized by a Fourier transform infrared spectroscopy pattern asshown in FIG. 4, a crystalline zoledronic diammonia water complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 17or characterized by a Fourier transform infrared spectroscopy pattern asshown in FIG. 18, a crystalline zoledronic acid, L-lysine, and watercomplex characterized by a powder x-ray diffraction pattern as shown inFIG. 5 or 25, or characterized by a Fourier transform infraredspectroscopy pattern as shown in FIG. 6 or 26, a crystalline zoledronicacid, DL-lysine, and water complex characterized by a powder x-raydiffraction pattern as shown in FIG. 7, 19, 21, or 23, or characterizedby a Fourier transform infrared spectroscopy pattern as shown in FIG. 8,20, 22, or 24, a crystalline zoledronic acid, zoledronic, DL-lysine,ethanol, and water complex characterized by a powder x-ray diffractionpattern as shown in FIG. 9 or characterized by a Fourier transforminfrared spectroscopy pattern as shown in FIG. 10, a crystallinezoledronic acid, adenine, and water complex characterized by a powderx-ray diffraction pattern as shown in FIG. 13 or characterized by aFourier transform infrared spectroscopy pattern as shown in FIG. 14, acrystalline zoledronic acid, nicotinamide, and water complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 11or characterized by a Fourier transform infrared spectroscopy pattern asshown in FIG. 12, and a crystalline zoledronic acid and glycine complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 15or characterized by a Fourier transform infrared spectroscopy pattern asshown in FIG.
 16. 2. A pharmaceutical composition comprising acomposition of claim 1 and a pharmaceutically acceptable excipient.
 3. Apharmaceutical composition of claim 1 wherein the pharmaceuticalcomposition is an oral dosage form.
 4. A pharmaceutical composition ofclaim 2 further comprising an excess amount of lysine.
 5. A zoledronicacid, DL-lysine and water complex, wherein the complex is a crystalline.6. A molecular complex of claim 5 wherein the molecular complex is acrystalline molecular complex selected from the group consisting of: acrystalline zoledronic acid, DL-lysine, and water complex characterizedby an X-ray powder diffraction pattern having peaks at about 8.3, 11.8,12.3, 15.8, and 20.8 ±0.2 degrees two-theta; a crystalline zoledronicacid, DL-lysine, and water complex characterized by an X-ray powderdiffraction pattern having peaks at about 9.1, 14.7, 18.0, 21.2, and26.0 ±0.2 degrees two-theta; a crystalline zoledronic acid, DL-lysine,and water complex characterized by an X-ray powder diffraction patternhaving peaks at about 9.7, 10.8, 14.4, 18.9, 21.4 ±0.2 degreestwo-theta; and a crystalline zoledronic acid, zoledronic, DL-lysine,ethanol, and water complex characterized by an X-ray powder diffractionpattern having peaks at about 8.8, 9.7, 17.6, 23.1, and 26.5 ±0.2degrees two-theta.
 7. A pharmaceutical composition comprising acomposition of claim 5 and a pharmaceutically acceptable excipient.
 8. Apharmaceutical composition of claim 7 wherein the pharmaceuticalcomposition is an oral dosage form.
 9. A pharmaceutical composition ofclaim 7 further comprising an excess amount of lysine.
 10. A crystallinemolecular complex of zoledronic acid of claim 1 selected from acrystalline zoledronic acid, sodium zoledronate, and water complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 1or characterized by a Fourier transform infrared spectroscopy pattern asshown in FIG.
 2. 11. A crystalline molecular complex of zoledronic acidof claim 1 selected from a crystalline ammonium zoledronic acid salt andwater complex characterized by a powder x-ray diffraction pattern asshown in FIG. 3 or characterized by a Fourier transform infraredspectroscopy pattern as shown in FIG.
 4. 12. A crystalline molecularcomplex of zoledronic acid of claim 1 selected from a crystallinezoledronic diammonia water complex characterized by a powder x-raydiffraction pattern as shown in FIG. 17 or characterized by a Fouriertransform infrared spectroscopy pattern as shown in FIG.
 18. 13. Acrystalline molecular complex of zoledronic acid of claim 1 selectedfrom a crystalline zoledronic acid, L-lysine, and water complexcharacterized by a powder x-ray diffraction pattern as shown in FIG. 5or 25, or characterized by a Fourier transform infrared spectroscopypattern as shown in FIG. 6 or
 26. 14. A crystalline molecular complex ofzoledronic acid of claim 1 selected from a crystalline zoledronic acid,DL-lysine, and water complex characterized by a powder x-ray diffractionpattern as shown in FIG. 7, 19, 21, or 23, or characterized by a Fouriertransform infrared spectroscopy pattern as shown in FIG. 8, 20, 22, or24.
 15. A crystalline molecular complex of zoledronic acid of claim 1selected from a crystalline zoledronic acid, zoledronic, DL-lysine,ethanol, and water complex characterized by a powder x-ray diffractionpattern as shown in FIG. 9 or characterized by a Fourier transforminfrared spectroscopy pattern as shown in FIG.
 10. 16. A crystallinemolecular complex of zoledronic acid of claim 1 selected from acrystalline zoledronic acid, adenine, and water complex characterized bya powder x-ray diffraction pattern as shown in FIG. 13 or characterizedby a Fourier transform infrared spectroscopy pattern as shown in FIG.14.
 17. A crystalline molecular complex of zoledronic acid of claim 1selected from a crystalline zoledronic acid, nicotinamide, and watercomplex characterized by a powder x-ray diffraction pattern as shown inFIG. 11 or characterized by a Fourier transform infrared spectroscopypattern as shown in FIG.
 12. 18. A crystalline molecular complex ofzoledronic acid of claim 1 selected from a crystalline zoledronic acidand glycine complex characterized by a powder x-ray diffraction patternas shown in FIG. 15 or characterized by a Fourier transform infraredspectroscopy pattern as shown in FIG.
 16. 19. A method for enhancing thebioavailability or permeability of zoledronic acid or salt thereofcomprising the step of administering to a patient in need thereof atherapeutically effective amount of zoledronic acid in the form of amolecular complex according to claim
 1. 20. A method for the treatmentof disease states associated with osteoporosis, hypercalcemia, cancerinduced bone metastasis, Paget's disease or adjuvant or neoadjuvantcancer therapies comprising the step of administering to a patient inneed thereof a therapeutically effective amount of a molecular complexaccording to claim
 1. 21. A method for enhancing the bioavailability orpermeability of zoledronic acid or salt thereof comprising the step ofadministering to a patient in need thereof a therapeutically effectiveamount of zoledronic acid in the form of a molecular complex accordingto claim
 5. 22. A method for the treatment of disease states associatedwith osteoporosis, hypercalcemia, cancer induced bone metastasis,Paget's disease or adjuvant or neoadjuvant cancer therapies comprisingthe step of administering to a patient in need thereof a therapeuticallyeffective amount of a molecular complex according to claim 5.